"I think the contestants fall in love with the romantic atmosphere not the lead. "Several past 'contestants' have admitted just that. They're removed from all contact with the world, the setting is ultra romantic, there's a whole lotta alcohol. They're set up to fall falsely in love (or fall in deep infatuation).
It could be that Andi wasn't feeling it half way through, but decided to stick around long enough to be considered for the next 'ette, so I agree with you there.
I'm wondering if it was mostly the Clare comment, during the overnight, that pushed Andi over the edge. Juan Pablo says that they talked and laughed all night (his story). Andi claims that he only talked about himself. I believe her, but I think she could've told him that during the overnight. I think it might be that his mention of CLARE during HER overnight got under her skin so much that she wanted out, then she blamed it on him only talking about himself.